Coprinus comatus (Shaggy Ink Cap)

The fruit body is a mushroom with cap atop a central stem. In contrast to most mushroom-producing species the cap is much taller than wide, up to 15 centimetres tall and 6 in diameter. The cap is brown at the top, otherwise mostly white and with abundant shaggy scales. The gills are white to pink but later appear black because that is the colour the spores become when mature. The white stem may be up to 15 centimetres long and 2 in diameter.

When young little of the stem is visible because the sides of the cap come down a long way over the stem (just as in a folded umbrella the closed canopy hides most of the shaft). For example, you see very little of the stem in this sighting: http://canberra.naturemapr.org/Community/Sighting/35312.

Over time the cap dissolves into an inky mess and slowly disappears, starting from the bottom and working up, until all that is left is the stem and, at its apex, the top of the mushroom cap (as in this sighting http://canberra.naturemapr.org/Community/Sighting/3377395).

A veil remnant is left on the stem as a ring, but this is loose and likely to fall to the bottom of the stem.

Spores: black.

This is commonly found on the ground in disturbed areas (e.g. parks, gardens and roadsides).

It should not  be possible to mistake this for any other species.